Francisco Javier Setoain

Anteroposterior versus lateral bone mineral density of spine assessed by dual X-ray absorptiometry.

Recently, it has been suggested that lateral (LAT) spine bone mass measurements by absorptiometry may be more sensitive for detecting bone loss than the standard anteroposterior (AP) projection. The aim of this study was to evaluate the precision of LAT spine dual-energy X-ray absorptiometry (DEXA) and its diagnostic sensitivity. A group of 1554 subjects with no risk factors that might affect bone metabolism and 185 osteoporotic patients with vertebral fractures were studied. Bone mineral density (BMD) was measured in the lumbar spine (standard AP and LAT projections) and proximal femur with a DEXA absorptiometer. The precision of the measurements was assessed in 15 volunteers. Diagnostic sensitivity was evaluated by the Z-score method. Comparing young people and the elderly, spine bone loss in the latter was similar for AP and LAT projections, when it was evaluated in absolute values (glcm2). However, when it was evaluated in percentage terms, bone loss was about twice as high in the LAT projection. LAT spine BMD correlated significantly with all the other areas assessed. The best correlation was found with the standard AP projection (r=0.67,P<0.0001). The precision in the LAT projection was found to be within an acceptable range (1.6% in normal subjects, 2% in osteoporotic patients), even though it was about twice that obtained in the AP projection. Diagnostic sensitivity was also better with the AP projection. It is concluded that LAT spine BMD measurements can be assessed with acceptable precision although it is about twice as high as for AP spine measurements. The percentage decrease in BMD in the elderly is greater for measurements made in the LAT projection than for measurements made in the AP projection. However, there is no enhancement of diagnostic sensitivity in osteoporosis. BMD measurements in the LAT projection are not as good as in the AP projection but they may offer complementary information of the regional evolution of spine bone mass.

Limitations of Gallium-67 SPECT in histological transformation of chronic lymphocytic leukaemia: an analysis of 13 patients with clinically suspected Richter's syndrome

Summary.  Gallium‐67 single photon emission computerized tomography (Ga‐67 SPECT) was performed in 13 chronic lymphocytic leukaemia (CLL) patients suspected of evolution into diffuse large B‐cell lymphoma (DLCL) or Richters syndrome (RS). Six positive and nine negative Ga‐67 SPECTs were observed. Ten patients were biopsied (five in each group). DLCL was not detected in any Ga‐67‐positive patient, including those in whom Ga‐67‐positive areas were biopsied. The only case of DLCL was demonstrated in a Ga‐67‐negative patient. The tumoral proliferative index (Ki67 antigen expression) was moderate and similar in both groups of patients. These results illustrate the limitations of Ga‐67 SPECT in identifying RS.

Technetium 99m-labeled tetrofosmin and iodine 123-labeled metaiodobenzylguanidine scintigraphy in the assessment of transmyocardial laser revascularization

OBJECTIVE Transmyocardial laser revascularization is a new technique that improves symptoms in patients with refractory angina not amenable to conventional revascularization. The aim of this study was to assess whether transmyocardial laser revascularization produces changes in innervation, perfusion scintigraphy, or both that could explain the benefit to patients. METHODS Sixteen patients (12 men and 4 women; mean age, 60 +/- 8 years) with coronary artery disease were studied. Transmyocardial laser revascularization was performed in 39 myocardial areas supplied by a stenotic vessel. A technetium 99m-labeled tetrofosmin stress-rest tomographic scan and iodine 123-labeled metaiodobenzylguanidine planar scans were performed before and after transmyocardial laser revascularization (3 and 12 months later) to evaluate myocardial perfusion and innervation. Stress and rest perfusion images were quantified on a polar map. Ischemia uptake was also defined as the difference between rest and stress uptake for each area. Innervation planar images were visually analyzed and semiquantified. RESULTS A significant decrease in angina class from baseline was observed at 3, 6, and 12 months after transmyocardial laser revascularization (P <.005). A significant decrease in ischemia uptake was also found between the pre-transmyocardial laser revascularization and the post-transmyocardial laser revascularization studies in treated areas (P <.001). A significant improvement in stress myocardial perfusion at 3 and 12 months after transmyocardial laser revascularization was only found in treated areas that were considered ischemic in the pre-transmyocardial laser revascularization study (P <.05). At 3 months, a significant myocardial innervation worsening was observed in treated areas (P <.001), with partial recovery at 12 months (P <.05). CONCLUSION The transmyocardial laser revascularization mechanism involves both perfusion improvement and denervation, mainly at 3 months, that partially recovered at 12 months.

123Iodine-labelled anti-VCAM-1 antibody scintigraphy in the assessment of experimental colitis.

Objectives To evaluate the usefulness of 123I-labelled anti-vascular cell adhesion molecule-1 (VCAM-1) monoclonal antibody (MAb) scintigraphy in the assessment of colonic inflammatory damage. Design Colitis was induced by intracolonic administration of 30 mg trinitrobenzenesulphonic acid in 0.5 ml of 50% (v/v) ethanol. Rats injected with vehicle served as controls. Animals were studied at day 7 after induction of colitis. Methods Scintigraphy was performed in control and trinitrobenzenesulphonic acid-induced colitic rats 2, 4 and 24 h after intravenous administration of 123I-anti-VCAM-1 MAb. Scintigraphic uptake was quantified in selected areas on scintigraphs. Animals were killed, tissue 123I radioactivity accumulation was measured, and accumulation of anti-VCAM-1 MAb in each organ was calculated. 99mTc-hexamethyl propylene amine oxime-labelled leucocyte scintigraphy was performed in additional groups of animals for comparison. Results Colonic tracer uptake was visible in scans of colitic, but not control animals. Quantification of scintigraphic uptake in the colon was significantly higher in colitic rats than in control animals (P < 0.0001). The specificity of the increase was demonstrated by lack of 123I-labelled non-binding MAb uptake in the colon, and by displacement of 123I-anti-VCAM-1 MAb colonic uptake by pre-treatment with unlabelled MAb. Accumulation of anti-VCAM-1 MAb in the colon of colitic rats was eightfold higher than in control animals. Strong correlations were found between quantification of scintigraphic uptake, anti-VCAM-1 MAb accumulation, histological damage and myeloperoxidase activity in the colon. Conclusion 123I-labelled anti-VCAM-1 MAb scintigraphy allows an accurate evaluation of colonic inflammatory damage in trinitrobenzenesulphonic acid-induced colitis, suggesting a potential role for this imaging technique in the assessment of human IBD.

Bases anatomopatológicas de la disfunción ventricular latente en diabéticos insulinodependientes

Introduccion y objetivos La historia natural dela miocardiopatia diabetica no esta bien definida,debido principalmente a la comun asociacion conenfermedad coronaria e hipertension arterial. Dadoque estas dos entidades son infrecuentes en los pacientesjovenes, estos constituyen un modelo adecuadopara el estudio de la miocardiopatia diabeticaen sus fases incipientes. Pacientes y metodos Se estudiaron 33 pacientesafectados de diabetes mellitus tipo I sin antecedentesde hipertension arterial ni enfermedad coronaria.Su edad media era de 28 ± 8 anos (rango, 18-46anos) y 14 eran varones. Resultados En el ecocardiograma se observo unventriculo izquierdo de tamano normal y sin anomaliasde la motilidad segmentaria, excepto en uncaso. En la ventriculografia isotopica se detectouna fraccion de eyeccion basal del 56,5 ± 6,6% queaumento al 63 ± 7,4% (p Conclusiones La disfuncion ventricular latentees un hallazgo frecuente en los pacientes diabeticosjovenes asintomaticos, y esta no es secundaria aaterosclerosis coronaria ni a enfermedad de pequenovaso. En este grupo de pacientes las anomaliashistologicas son constantes y se manifiestan por fibrosisintersticial, hipertrofia celular, miocitolisis ydepositos lipidicos.

Noninvasive assessment of cardiac risk in type I diabetic patients being evaluated for combined pancreas‐kidney transplantation using dipyridamole‐MIBI perfusion

Abstract This study was performed to determine the value of dipyridamole‐99 mTc‐methoxy‐isobutyl isonitrile perfusion (99mTC‐MIBI) tomographic scintigraphy in the assessment of cardiac risk in patients being evaluated prior to combined pancreas‐kidney transplantation (PKT). We performed perfusion tomographic scintigraphy using single photon emission computed tomography (SPECT) on 77 patients. The tomographic images did not show clinically relevant findings in 65 patients. In the remaining 12 patients, coronary arteriography was performed: 2 showed normal results, 4 showed no stenosis, and 6 showed significant stenosis (≥ 70%). Seventy‐two patients underwent PKT. During the follow‐up (6–48 months), there were seven cardiac events, 4 patients with significant stenosis, and 3 with nonsignificant stenosis upon coronary arteriography, and all had pathological tomographic images. 99mTc‐MIBI tomographic scintigraphy may be useful in identifying patients at low risk of incurring cardiac events after PKT and may, in a large group of patients, obviate the need for routine coronary angiography.

Gallbladder visualization on RBC scintigraphy.

The gallbladder was observed 24 hours after labeled RBC reinjection on a Tc-99m RBC gastrointestinal bleeding site imaging study. in come cases, the presence of the tracer in the gallbladder could represent hematobilia. in other cases, it may also be due to Tc-99m labeled to the porphyrin portion of hemoglobin.

Indium-111 labelled platelet scintigraphy can predict the immunological origin of fever in patients on dialysis carrying a non-functioning renal allograft.

Abstract.The purpose of this study was to evaluate the usefulness of labelled platelet scintigraphy in the differential diagnosis of a prolonged febrile syndrome (PFS) in patients on dialysis carrying a non-functioning renal allograft. We prospectively performed an indium-111 mercaptopyridine-labelled platelet scan on 91 patients (54 men, 37 women; mean age 39.6±12 years). The mean duration of PFS was 35 days (range 7–122). Forty-six of the 91 patients underwent steroid therapy (2– 10 mg/day). Platelet labelling was carried out following Thakur’s method. Platelet scans were performed 48 h after reinjection of labelled platelets. The platelet uptake index (PUI) was calculated by dividing the cpm/pixel in the allograft ROI by cpm/pixel in a mirror background ROI. The final diagnosis of PFS was established depending on the outcome after treatment. In 61/91 patients the fever had an immunological origin because it disappeared after graft embolisation or transplantectomy. In 30/91 patients the PFS disappeared after antibiotic therapy (non-immunological origin). The PUI in patients with immunological PFS was 1.80±0.7, while in patients with non-immunological PFS it was 1.12±0.1 (P<0.05). When a PUI of ≥1.5 was considered as the threshold to establish PFS of immunological origin, the sensitivity of platelet scan was 76%, the specificity 100%, and the negative and positive predictive values 69% and 100%, respectively. In patients classified with immunological PFS who underwent steroid therapy, the PUI was significantly lower than in patients without steroids (P<0.05). These results suggest that 111In-labelled platelet scintigraphy can accurately predict an immunological PFS in patients on dialysis carrying a non-functioning renal allograft. Therapy with steroids could reduce the sensitivity of 111In-labelled platelet scintigraphy in detecting immunological PFS.

Tc-99m labeled nonspecific polyclonal human immunoglobulin G taken up by a uterine myoma

A 71-year-old woman had a Tc-99m labeled nonspecific polyclonal human immunoglobin G (HIG) scintigraphy to test for synovitis. The scans showed an intense uptake in a pelvic mass, which was confirmed to be a calcified uterine myoma. Labeled HIG scintigraphy was introduced for the detection of inflammation. Although uptake of Tc-99m HIG has been shown in malignant lesions in patients without inflammation, this case indicates that uptake in benign tumors must also be taken into account.

Bladder herniation detected on a bone scan

Tc-99m MDP bone imaging was performed on a 66-year-old man with known prostatic adenocarcinoma. A large area increased activity in the right inguinal area was observed. Dynamic imaging with Tc-99m pertechnetate showed a photopenic area at the same site, which filled in with the patient standing erect. This demonstrated that the lesion corresponded to a bladder hernia, which the patient had previously refused to have repaired.